Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4880065 | Air motor operated rotary earth drilling tool | William J. McDonald, Michael R. Wasson, Curtis E. Leitko, Jr., Gerard T. Pittard | 1989-11-14 |
| 4858704 | Guided earth boring tool | William J. McDonald, Gerard T. Pittard, Michael R. Wasson, William Christian Herben | 1989-08-22 |
| 4828053 | Deviated wellbore drilling system and apparatus | William J. McDonald | 1989-05-09 |